I owe an apology to the gerbil community and their friends. For too long, I have dismissed these wee sand rats as unworthy of a whole page. I don't have any personal antipathy towards gerbils - they're sweet enough, in a rodenty sort of way - I just couldn't think of anything interesting to say about them. In desperation, I turned to Fur & Feather magazine, and there it was in the listings: a National Gerbil Society show. Surely that experience alone would furnish at least one paragraph with interesting gerbil material?

Consequently, I soon found myself looking at dozens of rodents in their little carry cases, some curious and alert, others huddled in a mass ball of gerbil. All were indisputably cute, but what else is there to say? Julian Barker, archivist and webmaster of the National Gerbil Society, was on hand to dazzle me with fascinating facts. So, here's the lowdown on gerbils.

They come from north Africa, the Middle East, central Asia and parts of China. There are about 90 species in the wild, but most pets are of the Mongolian variety. The Latin name for the Mongolian gerbil is Meriones unguiculatus; tellingly, Meriones is also the name of a Greek soldier in Homer's Iliad, and "unguiculatus" means "with fingernails". The gerbil's name may suggest antiquity, but the burrowing rodent was largely ignored until relatively recently. Gerbils were never worshipped as Egyptian gods or adorned with jewels in Roman palaces. They were first described in the 1860s by the French missionary Pere David, the man responsible for identifying the panda.

But how did gerbils, of all the rodent species in the world, end up a popular pet? A Japanese scientist collected specimens from Mongolia in the 1950s, some of which were exported to America and the UK. They were, and still are, used in laboratory experiments, but, somewhere along the line, they also became pets. Gerbils live along the hippy trail, so it's only fitting that they flower-powered their way to official recognition in 1970, when the National Gerbil Society was founded. That relatively recent introduction of the species explains why gerbils never received the Beatrix Potter treatment.

Gerbils make good pets because they are awake during the day and they don't bite. Because their natural habitat is arid terrain, they are keen on water conservation, so they don't pee very much, and this means they don't smell. Like their fellow rodents, however, they are very good at multiplication. Female gerbils mate within hours of giving birth.

The most bizarre snippet of gerbil trivia relates to their role in covert security operations. In 2001, it was revealed that MI5 had attempted to turn gerbils into secret agents during the cold war. Gerbils have a strong sense of smell and can be trained to identify a really sweaty person. The idea was that gerbils would be able to whiff out suspicious characters.

The Israeli security service tested these espionage rodents in Tel Aviv airport. It turned out, however, that gerbils are unable to distinguish between someone who's sweating profusely because they've got too many knick-knacks in their luggage and someone who's about to hijack a plane. MI5 quickly decided that gerbils were an inadequate tool in the fight to save the world from communism.

That's the official line, anyway. My hunch is that the gerbils - native to many parts of the former Soviet Union as well as China - were simply double agents. So, there you have it. I now know at least one fact about gerbils that's interesting enough to share down the pub. But that still leaves me with one problem - whatever is there to say about hamsters?